1. Field of the Invention
This invention relates to a medical device, in a preferred embodiment a syringe, either traditional or pre-filled, having a recessed nose and a forwardly projecting, protective guard that cooperate to reduce the likelihood of contamination from accidental or inadvertent contact. The syringe of the invention is intended for use in combination with a frontal attachment such as, for example, a sealing cap, a safety cap, a needle assembly, a luer connector, a CLAVE® connector for introducing liquid into a closed IV system, or another vascular access connector or other proprietary or commercially available frontal attachments. The invention also relates to a structure that protects the nose of a syringe from contamination by contact while simultaneously providing full engagement between cooperating surfaces of a connector provided for frontal attachment to the syringe and reducing the likelihood of disengagement during use. The invention also relates to a method for protecting the tip of a luer connector from contamination without reducing the engagement surface area between the luer of a frontal attachment and the nose of a syringe, thereby reducing the likelihood of fluid leakage at the connection between the frontal attachment and the syringe.
2. Description of Related Art
Catheter-associated bloodstream infections reported from hospitals across the United States have increased since the introduction of needleless devices. According to the U.S. Center for Disease Control, an estimated 250,000 catheter-related bloodstream infections occur in U.S. hospitals each year. Catheter-related infections can cost the U.S. healthcare system up to $25,000 per episode or more. As many as 28,000 patients die each year in the U.S. because of catheter-related bloodstream infections.
Syringes that utilize frontal attachments such as sealing caps or various types of connectors rather than fixed needles or preset retractable needles for storing, administering or withdrawing medications or fluids are known in the prior art. Syringes made for use with frontal attachments include pre-filled syringes and standard syringes that are shipped without an affixed needle. Such conventional syringes frequently comprise an annular skirt, collar or other opening at or near the front of the syringe barrel in combination with a smaller-diameter nose portion that extends forwardly beyond the annular skirt or collar at the front end of the barrel. Some syringes with attachable needles have a safety mechanism that encircles a portion of the nose but does not protect the tip from contact prior to use. Other syringes have a protective sheath that the user can slide forward over a needle following use.
Some syringes having a radially spaced-apart annular skirt or collar surrounding a part of the nose also comprise structural elements useful for attaching a needle assembly or other connector to the syringe. With pre-filled syringes, the forwardly extending end of the nose portion is generally either sealed with a membrane to prevent loss of the pre-filled medicament prior to use, or else the syringe is provided with a removable sealing cap that is removed before the needle assembly or connector is attached to the syringe barrel. Once the sealing membrane has been punctured or the sealing cap has been removed, the syringe plunger is depressed and pre-filled liquid flows through the attachment.
Two commercially available types of frontal attachments or connectors are, for example, a CLAVE® connector and a luer connector. The CLAVE brand connector is marketed by ICU Medical and disclosed in U.S. Pat. No. 5,694,686. The CLAVE® connector has a rearwardly facing needle or other sharp object that punctures a sealing membrane in the forwardly extending nose of a prefilled syringe as the connector is threaded into engagement with a collar on the syringe barrel. Following attachment of the CLAVE® connector to both the syringe barrel and to an IV injection port, the syringe plunger is depressed and the pre-filled liquid flows out of the syringe through the shaft of the puncturing needle, through the body of the connector and into the closed intravenous (“IV”) injection system. Other syringes that do not have a permanently affixed needle frequently use a frontal attachment comprising a needle and a luer fitting that is attachable to a cooperatively configured syringe barrel. A luer needle attachment typically has either a flange or external threads that are alignable and engageable with cooperating structural elements disposed inside the annular skirt portion near the front of a syringe barrel.
Although both types of conventional syringes as discussed above commonly have an annular skirt near the front of the syringe barrel, such conventional syringes are not known to embody a structure that effectively protects or guards the forwardly extending nose portion of the syringe barrel from contamination by direct contact. Such contact can result in the accidental injection of harmful bacteria or other pathogens into a patient's body, thereby contributing to the spread of disease and potentially fatal bacterial or viral infections within supposedly sterile healthcare environments. This risk is believed to be reduced significantly by the invention disclosed and claimed herein.